关键词: 谐振子, 矩阵元, 粒子数态, 相干态, 产生和湮没算符, 正规乘积

Abstract: The problems of simply and directly computing the matrix elements of coordinate operator for the harmonic oscillator in both the number states and the coherent states representations are studied in detail,the explicit procedures are given and some issues related to the methods and procedures in the literatures are commented.

Key words: harmonic oscillator, matrix element, creation and destroy operators, coherent state, number state, normal order product